单项选择题
Which of the following may hardness of the boiler water cause?（） (1) scale formation (2) tube failure (3) corrosion
A.（1）and（2） B.（1）and（3） C.（2）and（3） D.（1），（2）and（3）
The water level showing in a boiler water gauge glass i...
单项选择题The water level showing in a boiler water gauge glass is usually （） during working.
A.higher than the actual drum water level B.equal to the actual drum water level C.increasing due to steam condensation in the glass D.lower than actual drum water level
A dazzling white burner flame in the boiler furnace ind...
单项选择题A dazzling white burner flame in the boiler furnace indicates （）.
A.no combustion B.deposits in the fuel C.excessive air in the fuel D.cold fuel oil
When the boiler load returns to normal, the drum pressu...
单项选择题When the boiler load returns to normal, the drum pressure will rise and steam bubble formation will reduce, causing a fall in water level This is known as （）.
A.swell B.shrinkage C.flash off D.lack of water
